Household carbon monoxide (CO) concentrations in a large African city: An unquantified public health burden?

Carbon monoxide (CO) is a poisonous gas produced by incomplete combustion of carbon-based fuels that is linked to mortality and morbidity. Household air pollution from burning fuels on poorly ventilated stoves can lead to high concentrations of CO in homes. There are few datasets available on household concentrations of CO in urban areas of sub-Saharan African countries. CO was measured every minute over 24 h in a sample of homes in Nairobi, Kenya. Data on household characteristics were gathered by questionnaire. Metrics of exposure were summarised and analysis of temporal changes in concentration was performed. Continuous 24-h data were available from 138 homes. The mean (SD), median (IQR) and maximum 24-h CO concentration was 4.9 (6.4), 2.8 (1.0-6.3) and 44 ppm, respectively. 50% of homes had detectable CO concentrations for 847 min (14h07m) or longer during the 24-h period, and 9% of homes would have activated a CO-alarm operating to European specifications. An association between a metric of total CO exposure and self-reported exposure to vapours >15 h per week was identified, however this were not statistically significant after adjustment for the multiple comparisons performed. Mean concentrations were broadly similar in homes from a more affluent area and an informal settlement. A model of typical exposure suggests that cooking is likely to be responsible for approximately 60% of the CO exposure of Nairobi schoolchildren. Household CO concentrations are substantial in Nairobi, Kenya, despite most homes using gas or liquid fuels. Concentrations tend to be highest during the evening, probably associated with periods of cooking. Household air pollution from cooking is the main source of CO exposure of Nairobi schoolchildren. The public health impacts of long-term CO exposure in cities in sub-Saharan Africa may be considerable and should be studied further.

Particulate matter in aerosols produced by two last generation electronic cigarettes: a comparison in a real-world environment

The design of e-cigarettes (e-cigs) is constantly evolving and the latest models can aerosolize using high-power sub-ohm resistance and hence may produce specific particle concentrations. The aim of this study was to evaluate the aerosol characteristics generated by two different types of electronic cigarette in real-world conditions, such as a sitting room or a small office, in number of particles (particles/cm3). We compared the real time and time-integrated measurements of the aerosol generated by the e-cigarette types Just Fog and JUUL. Real time (10s average) number of particles (particles/cm3) in 8 different aerodynamic sizes was measured using an optical particle counter (OPC) model Profiler 212-2. Tests were conducted with and without a Heating, Ventilating Air Conditioning System (HVACS) in operation, in order to evaluate the efficiency of air filtration. During the vaping sessions the OPC recorded quite significant increases in number of particles/cm3. The JUUL e-cig produced significantly lower emissions than Just Fog with and without the HVACS in operation. The study demonstrates the rapid volatility or change from liquid or semi-liquid to gaseous status of the e-cig aerosols, with half-life in the order of a few seconds (min. 4.6, max 23.9), even without the HVACS in operation. The e-cig aerosol generated by the JUUL proved significantly lower than that generated by the Just Fog, but this reduction may not be sufficient to eliminate or consistently reduce the health risk for vulnerable non e-cig users exposed to it.

Measurement of SARS-CoV-2 in air and on surfaces in Scottish hospitals

BACKGROUND

There are still uncertainties in our knowledge of the amount of SARS-CoV-2 virus present in the environment - where it can be found, and potential exposure determinants - limiting our ability to effectively model and compare interventions for risk management.

AIM

This study measured SARS-CoV-2 in three hospitals in Scotland on surfaces and in air, alongside ventilation and patient care activities.

METHODS

Air sampling at 200 L/min for 20 min and surface sampling were performed in two wards designated to treat COVID-19-positive patients and two non-COVID-19 wards across three hospitals in November and December 2020.

FINDINGS

Detectable samples of SARS-CoV-2 were found in COVID-19 treatment wards but not in non-COVID-19 wards. Most samples were below assay detection limits, but maximum concentrations reached 1.7×10³ genomic copies/m³ in air and 1.9×10⁴ copies per surface swab (3.2×10² copies/cm² for surface loading). The estimated geometric mean air concentration (geometric standard deviation) across all hospitals was 0.41 (71) genomic copies/m³ and the corresponding values for surface contamination were 2.9 (29) copies/swab. SARS-CoV-2 RNA was found in non-patient areas (patient/visitor waiting rooms and personal protective equipment changing areas) associated with COVID-19 treatment wards.

CONCLUSION

Non-patient areas of the hospital may pose risks for infection transmission and further attention should be paid to these areas. Standardization of sampling methods will improve understanding of levels of environmental contamination. The pandemic has demonstrated a need to review and act upon the challenges of older hospital buildings meeting current ventilation guidance.

'They only smoke in the house when I'm not in': understanding the limited effectiveness of a smoke-free homes intervention

Background

Children’s second-hand smoke (SHS) exposure in the home is highest in socio-economically disadvantaged areas. Personalized household air-quality measurements can promote changes in smoking that reduce SHS exposure. The ‘First Steps 2 Smoke-free’ (FS2SF) intervention is the first to trial this approach delivered as part of health professionals’ routine work. This paper reports the findings of qualitative interviews with participants that explored their experiences of the intervention and why outcomes varied.

Methods

120 women were recruited from the NHS First Steps Programme, which supports disadvantaged mothers. They received either personalized feedback on their home air quality and advice on reducing SHS or standard SHS advice. Qualitative interviews with 15 mothers were analyzed thematically using the Capability, Opportunity, Motivation, Behaviour (COM-B) model.

Results

The intervention increased women’s capability to change home-smoking behaviour, through increasing awareness and salience of SHS risks to their children, and motivation to act. However, taking effective action was constrained by their limited social and environmental opportunities, including others’ smoking in the home.

Conclusions

The FS2SF intervention was ineffective as it was unable to fully address the precarious, complex life circumstances that make creating a smoke-free home particularly difficult for women experiencing intersecting dimensions of disadvantage.

Diurnal variability of fine-particulate pollution concentrations: data from 14 low- and middle-income countries

BACKGROUND: Scientific understanding of indoor air pollution is predominately based on research carried out in cities in high-income countries (HICs). Less is known about how pollutant concentrations change over the course of a typical day in cities in low- and middle-income countries (LMICs).OBJECTIVE: To understand how concentrations of fine particulate matter smaller than 2.5 microns in diameter (PM_2.5) change over the course of the day outdoors (across a range of countries) and indoors (using measurements from Dhaka, Bangladesh).DESIGN: Data on PM_2.5 concentrations were gathered from 779 households in Dhaka as part of the MCLASS II (Muslim Communities Learning About Second-hand Smoke in Bangladesh) project, and compared to outdoor PM_2.5 concentrations to determine the temporal variation in exposure to air pollution. Hourly PM_2.5 data from 23 cities in 14 LMICs, as well as London (UK), Paris (France) and New York (NY, USA), were extracted from publicly available sources for comparison.RESULTS: PM_2.5 in homes in Dhaka demonstrated a similar temporal pattern to outdoor measurements, with greater concentrations at night than in the afternoon. This pattern was also evident in 19 of 23 LMIC cities.CONCLUSION: PM_2.5 concentrations are greater at night than during the afternoon in homes in Dhaka. Diurnal variations in PM_2.5 in LMICs is substantial and greater than in London, Paris or New York. This has implications for public health community approaches to health effects of air pollution in LMICs.

Thrombus formation on bioprosthetic aortic valves

Background

18F-GP1 is a novel radiotracer with a high affinity for the platelet glycoprotein IIb/IIIa receptor. Subclinical bioprosthetic valve thrombus has been postulated as a trigger for accelerated valve degeneration.

Purpose

To determine the feasibility of 18F-GP1 positron-emission tomography-computed tomography (PET-CT) for the detection of subclinical bioprosthetic aortic valve thrombus.

Methods

(i) Explanted degenerated aortic valve prostheses underwent histology and imaging. (ii) In a prospective observational study, patients with bioprosthetic aortic valve replacement (AVR) underwent echocardiography and 18F-GP1 PET-CT. Valves were assessed for hypoattenuating leaflet thickening (HALT), hypo-attenuation affection leaflet motion (HAM) and GP1 uptake.

Results

(i) GP1 correlated with thrombus on explanted valves (Figure). (ii) The first 6 patients (Table) were asymptomatic and had normally functioning surgical bioprostheses on echocardiography. At a median of 166 (range 122–189) days post-AVR, no patients had HALT or HAM on CT. There was avid focal GP1 uptake on the leaflets of all 6 patients which appeared most prominent along the leaflet edges (Figure). Only one patient had focal uptake in the valve frame, remote from the leaflets. In a separate cohort undergoing 18F-GP1 PET-CT for other conditions, there was no uptake on normal, native aortic valves (n=8).

Conclusion

For the first time, we demonstrate that 18F-GP1 PET-CT is a highly sensitive method of assessing platelet activation on bioprosthetic aortic valves. Despite the absence of CT evidence, early thrombus appeared to be a universal finding on recently implanted valve prostheses. The biological and clinical implications of subclinical bioprosthetic aortic valve thrombus have yet to be established.

GP1 uptake in AVR

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation

How does smokefree policy impact nicotine-related and other prisoner spend (e.g. HFSS foods)?

Background

People in custody (PiC) have poor health compared to the general population, in part due to high smoking rates. Scotland's prisons became smokefree in 2018. Rechargeable e-cigarettes became available a few weeks before the removal of tobacco from the 'canteen' (prison shop for PiC).

Methods

Routinely collected weekly 'canteen' purchase data (no of units of given product purchased by an individual by date) were available for 29-7-18 to 31-3-19 (2112638 rows of data, 645 unique products). Products were categorised into: tobacco; e-cigarettes; food/drink; communication; hygiene; NRT; other and graphed as mean/person/week, for 'smokers' and 'non-smokers' (at baseline). Spend by product type pre- and post-implementation was compared in PiC for 31+ weeks over this period, using mixed effects models.

Results

Mean weekly spend for 'smokers' in custody for 31+ weeks over the pre-post ban comparison period (n = 2541) decreased from £21.36 to £19.80; mean weekly nicotine-related spend reduced from £6.64 (pre-) to £5.55 (post-) (p < 0.001), but showed an increasing trend in nicotine-related spend (£0.08/week) post-ban. No changes were seen for 'non-smokers' (n = 342) overall) or in nicotine-related spend. Trends in mean spend for other products remained flat, suggesting positive transfers of spend noted in qualitative interviews over a comparable period were not evident at population level.

Conclusions

Whilst there are benefits of removing tobacco from prisons, for staff and PiC, previously heavy smokers may find (mandated) tobacco abstinence difficult. Some jurisdictions have made e-cigarettes available to support people quitting/managing without tobacco, but long-term implications of e-cigarette use in this population are as yet unknown. When the introduction of smokefree policy is facilitated by the introduction of e-cigarettes, nicotine spend by PiC may remain high; the implications for whether or not PiC return to smoking on release from custody are unclear.

Changes in exposure to second-hand smoke following a smoking ban across a national prison system

Background

Prisons were one of few workplaces where smoking was still permitted after the smoking ban in indoor public places in Scotland in 2006. This study compares SHS exposure assessments in Scotland's 15 prisons six months after smokefree policy was introduced (in Nov 2018) with levels measured in 2016 before the policy was announced.

Methods

In 2016, 128,431 mins of PM2.5 (marker of SHS) concentration data were collected from residential halls and 2,860 mins for 'task-based' measures; 2019 figures were 126,777 and 3,073 mins. Six days of fixed-site monitoring in halls in each prison commenced on 22.5.19. Task-based measurements were conducted to assess SHS for specific locations and activities (e.g. cell searches). Typical daily PM2.5 exposure profiles were constructed for the prison service and time-weighted average exposure concentrations were estimated for shift patterns for residential staff pre- and post-implementation of the policy. Staff self-reports of exposure to SHS were gathered via surveys.

Results

Measured PM2.5 in residential halls declined markedly; median fixed-site concentrations reduced by > 91% compared to baseline. Changes in the task-based measurements (89% average decrease for high-exposure tasks) and time-weighted average concentrations across shifts (>90% decrease across all shifts), provide evidence that staff exposure to SHS has significantly reduced. The percentage of staff reporting no exposure to SHS rose post-ban.

Conclusions

This is the first study to objectively measure SHS levels before, during and after implementation of smokefree policy across a country's prison system. The dramatic reduction in SHS exposures confirm complementary qualitative data and stakeholder reports of the ban's success in removing tobacco. The findings show that SHS can be effectively eliminated through a well-applied smoking ban in the challenging context of prisons; and are highly relevant for other jurisdictions considering changes to prison smoking rules.

Differential visceral blood flow in the hyperdynamic circulation of patients with liver cirrhosis

BACKGROUND

With advancing liver disease and the development of portal hypertension, there are major alterations in somatic and visceral blood flow. Using phase-contrast magnetic resonance angiography, we characterised alterations in blood flow within the hepatic, splanchnic and extra-splanchnic circulations of patients with established liver cirrhosis.

AIM

To compare blood flow in splanchnic and extra-splanchnic circulations in patients with varying degrees of cirrhosis and healthy controls.

METHODS

In a single-centre prospective study, 21 healthy volunteers and 19 patients with established liver disease (Child's stage B and C) underwent electrocardiogram-gated phase-contrast-enhanced 3T magnetic resonance angiography of the aorta, hepatic artery, portal vein, superior mesenteric artery, and the renal and common carotid arteries.

RESULTS

In comparison to healthy volunteers, resting blood flow in the descending thoracic aorta was increased by 43% in patients with liver disease (4.31 ± 1.47 vs. 3.31 ± 0.80 L/min, P = 0.011). While portal vein flow was similar (0.83 ± 0.38 vs. 0.77 ± 0.35 L/min, P = 0.649), hepatic artery flow doubled (0.50 ± 0.46 vs. 0.25 ± 0.15 L/min, P = 0.021) and consequently total liver blood flow increased by 30% (1.33 ± 0.84 vs. 1.027 ± 0.5 L/min, P = 0.043). In patients with liver disease, superior mesenteric artery flow was threefold higher (0.65 ± 0.35 vs. 0.22 ± 0.13 L/min, P < 0.001), while total renal blood flow was reduced by 40% (0.37 ± 0.14 vs. 0.62 ± 0.22 L/min, P < 0.001) and total carotid blood flow unchanged (0.62 ± 0.20 vs. 0.65 ± 0.13 L/min, P = 0.315).

CONCLUSIONS

Rather than a generalised systemic hyperdynamic circulation, liver disease is associated with dysregulated splanchnic vasodilatation and portosystemic shunting that, while inducing a high cardiac output, causes compensatory extra-splanchnic vasoconstriction - the 'splanchnic steal' phenomenon. These circulatory disturbances may underlie many of the manifestations of advanced liver disease.

COPD: Is there evidence to support a role for resistance training in improving measurable health-related quality of life in pulmonary rehabilitation?

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality. As such, the disease places a significant burden on health care services. Although the pathogenesis of COPD is complex, progressive airflow limitation and a chronic inflammatory response are two hallmark characteristics of the disease. In addition, systemic manifestations such as peripheral muscle dysfunction have recently received considerable attention in the literature. Pulmonary rehabilitation is an evidence-based multidisciplinary intervention that has been shown to produce clinically relevant outcomes. One important component of rehabilitation is exercise. With the majority of COPD patients presenting with muscle weakness and exercise intolerance, the inclusion of resistance training into a pulmonary rehabilitation programme would seem appropriate. Compared with other exercise/training modalities only a small number of studies have investigated the effects of resistance training in COPD patients. Although further research is required to identify the optimal mode, intensity and frequency, it appears that resistance training may prove to be a valuable intervention for COPD patients enrolled in pulmonary rehabilitation programmes.

Perioperative elafin for ischaemia-reperfusion injury during coronary artery bypass graft surgery: a randomised-controlled trial

Background

Elafin is a potent endogenous neutrophil elastase inhibitor that protects against myocardial inflammation and injury in preclinical models of ischaemic-reperfusion injury. We investigated whether elafin could inhibit myocardial ischaemia-reperfusion injury induced during coronary artery bypass graft (CABG) surgery.

Methods and results

In a randomised double-blind placebo-controlled parallel group clinical trial, 87 patients undergoing CABG surgery were randomised 1:1 to intravenous elafin 200 mg or saline placebo administered after induction of anaesthesia and prior to sternotomy. Myocardial injury was measured as cardiac troponin I release over 48 h (area under the curve (AUC)) and myocardial infarction identified with MRI. Postischaemic inflammation was measured by plasma markers including AUC high-sensitive C reactive protein (hs-CRP) and myeloperoxidase (MPO). Elafin infusion was safe and resulted in >3000-fold increase in plasma elafin concentrations and >50% inhibition of elastase activity in the first 24 h. This did not reduce myocardial injury over 48 h (ratio of geometric means (elafin/placebo) of AUC troponin I 0.74 (95% CI 0.47 to 1.15, p=0.18)) although post hoc analysis of the high-sensitive assay revealed lower troponin I concentrations at 6 h in elafin-treated patients (median 2.4 vs 4.1 μg/L, p=0.035). Elafin had no effect on myocardial infarction (elafin, 7/34 vs placebo, 5/35 patients) or on markers of inflammation: mean differences for AUC hs-CRP of 499 mg/L/48 h (95% CI −207 to 1205, p=0.16), and AUC MPO of 238 ng/mL/48 h (95% CI −235 to 711, p=0.320).

Conclusions

There was no strong evidence that neutrophil elastase inhibition with a single-dose elafin treatment reduced myocardial injury and inflammation following CABG-induced ischaemia-reperfusion injury.

Trial registration number

(EudraCT 2010-019527-58, ISRCTN82061264).

Knowledge, attitude and perception of second-hand smoke and factors promoting smoking in Malaysian adolescents

OBJECTIVE

To identify the relationship between knowledge, attitude and perception regarding environmental tobacco smoke (ETS) and smoking among Malaysian adolescents living in states with complete or partial smoke-free legislation (SFL).

METHODS

A total of 898 respondents aged 13-14 years were randomly selected from 21 secondary schools. The Malay version of the modified Global Youth Tobacco Survey questionnaire was used. Hierarchical logistic regression was performed in examining predictors of smoking attempt among adolescents.

RESULTS

Participants exposed to ETS >5 h/day were more likely to have smoked compared to those exposed to ETS <1 h/day (OR 4.1, 95%CI 1.03-16.0). Living in a state with partial SFL was associated with a two-fold increase in self-reported smoking attempts (OR 1.95, 95%CI 1.10-3.43) compared to living in a state with complete SFL. Negative attitudes and perceptions towards smoking and ETS exposure were linked to lower smoking attempts in states with complete SFL.

CONCLUSIONS

Adolescents with limited ETS exposure who lived in a state with complete SFL were less likely to attempt smoking compared to those exposed more regularly to ETS and living in a state with partial SFL. Preventing adolescents from becoming smokers is the key to reducing national prevalence rates in smoking. There is a need to implement comprehensive smoke-free legislation nationally across Malaysia.

Low-dose dexamethasone as a treatment for women with heavy menstrual bleeding: protocol for response-adaptive randomised placebo-controlled dose-finding parallel group trial (DexFEM)

INTRODUCTION

Heavy menstrual bleeding (HMB) diminishes individual quality-of-life and poses substantial societal burden. In HMB endometrium, inactivation of cortisol (by enzyme 11β hydroxysteroid dehydrogenase type 2 (11βHSD2)), may cause local endometrial glucocorticoid deficiency and hence increased angiogenesis and impaired vasoconstriction. We propose that 'rescue' of luteal phase endometrial glucocorticoid deficiency could reduce menstrual bleeding.

METHODS AND ANALYSIS

DexFEM is a double-blind response-adaptive parallel-group placebo-controlled trial in women with HMB (108 to be randomised), with active treatment the potent oral synthetic glucocorticoid dexamethasone, which is relatively resistant to 11βHSD2 inactivation. Participants will be aged over 18 years, with mean measured menstrual blood loss (MBL) for two screening cycles ≥50 mL. The primary outcome is reduction in MBL from screening. Secondary end points are questionnaire assessments of treatment effect and acceptability. Treatment will be for 5 days in the mid-luteal phases of three treatment menstrual cycles. Six doses of low-dose dexamethasone (ranging from 0.2 to 0.9 mg twice daily) will be compared with placebo, to ascertain optimal dose, and whether this has advantage over placebo. Statistical efficiency is maximised by allowing randomisation probabilities to 'adapt' at five points during enrolment phase, based on the response data available so far, to favour doses expected to provide greatest additional information on the dose-response. Bayesian Normal Dynamic Linear Modelling, with baseline MBL included as covariate, will determine optimal dose (re reduction in MBL). Secondary end points will be analysed using generalised dynamic linear models. For each dose for all end points, a 95% credible interval will be calculated for effect versus placebo.

ETHICS AND DISSEMINATION

Dexamethasone is widely used and hence well-characterised safety-wise. Ethical approval has been obtained from Scotland A Research Ethics Committee (12/SS/0147). Trial findings will be disseminated via open-access peer-reviewed publications, conferences, clinical networks, public lectures, and our websites.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01769820; EudractCT 2012-003405-98.

Biomass fuel use and the exposure of children to particulate air pollution in southern Nepal

The exposure of children to air pollution in low resource settings is believed to be high because of the common use of biomass fuels for cooking. We used microenvironment sampling to estimate the respirable fraction of air pollution (particles with median diameter less than 4 μm) to which 7-9 year old children in southern Nepal were exposed. Sampling was conducted for a total 2649 h in 55 households, 8 schools and 8 outdoor locations of rural Dhanusha. We conducted gravimetric and photometric sampling in a subsample of the children in our study in the locations in which they usually resided (bedroom/living room, kitchen, veranda, in school and outdoors), repeated three times over one year. Using time activity information, a 24-hour time weighted average was modeled for all the children in the study. Approximately two-thirds of homes used biomass fuels, with the remainder mostly using gas. The exposure of children to air pollution was very high. The 24-hour time weighted average over the whole year was 168 μg/m(3). The non-kitchen related samples tended to show approximately double the concentration in winter than spring/autumn, and four times that of the monsoon season. There was no difference between the exposure of boys and girls. Air pollution in rural households was much higher than the World Health Organization and the National Ambient Air Quality Standards for Nepal recommendations for particulate exposure.

Low back pain among textile workers: a cross-sectional study

BACKGROUND

Low back pain (LBP) is one of the most prevalent occupational health problems in industrialized countries. Little is known about the epidemiology of LBP in developing countries.

AIMS

To determine the prevalence of LBP among Nepalese textile workers and to investigate the influence of exposure to mechanical and other factors on LBP reporting.

METHODS

Interviewers completed questionnaires with study subjects, and work-related mechanical exposures were measured by self-completed questionnaires. Associations of LBP with mechanical factors and somatic symptoms were determined by logistic regression and reported as odds ratios (ORs) with 95% confidence intervals (CI).

RESULTS

Nine hundred and thirty-eight workers took part, a participation rate of 92%. The 1 month period prevalence of LBP was 35% (n = 324), being higher in females than males (45% versus 28%; P < 0.001). Several work-related mechanical factors were associated with increased odds of reporting LBP: lifting heavy weights with one hand (OR 1.7; 95% CI 1.1-2.8), pushing weights (OR 1.6; 95% CI 1.2-2.3 and pulling weights (OR 1.6; 95% CI 1.1-2.1). No association was found with working posture. Strong associations were found for reporting one (OR 2.4; 95% CI 1.7-3.4) or two somatic symptoms (OR 2.7; 95% CI 1.4-5.1). On multivariable analysis, reporting of somatic symptoms (OR 2.8; 95% CI 1.5-5.4), female gender (OR 2.2; 95% CI 1.5-3.1) and increasing age were significantly associated with increased risk of reporting LBP (OR 1.7; 95% CI 1.2-2.5), but no associations were found with mechanical factors.

CONCLUSIONS

This study suggests that mechanical load may not be the leading cause of LBP and adds to evidence that psychological factors play an important role in LBP in non-industrialized countries.

Condom use among female sex workers and their non-commercial partners: effects of a sexual risk intervention in two Mexican cities

The purpose of this study was to examine whether a brief behavioural intervention promoting condom use among female sex workers (FSWs) and their clients had the added benefit of increasing condom use among FSWs and their steady, non-commercial partners (e.g. husbands, boyfriends). Participants were 362 FSWs, aged ≥18 years, living in Tijuana or Ciudad Juarez, Mexico, who received a behavioural intervention to promote condom use with clients. Repeated-measures negative binomial regression was used to assess FSWs' condom use with steady partners versus clients across time. Results showed that FSWs engaged in unprotected sex with steady partners more than with their clients, and that the intervention changed FSWs' condom use with clients but not their steady partners. HIV-prevention interventions for FSWs should promote consistent condom use across partner type. Targeting couples rather than individuals may also be necessary.

Contribution of solid fuel, gas combustion, or tobacco smoke to indoor air pollutant concentrations in Irish and Scottish homes

  There are limited data describing pollutant levels inside homes that burn solid fuel within developed country settings with most studies describing test conditions or the effect of interventions. This study recruited homes in Ireland and Scotland where open combustion processes take place. Open combustion was classified as coal, peat, or wood fuel burning, use of a gas cooker or stove, or where there is at least one resident smoker. Twenty-four-hour data on airborne concentrations of particulate matter<2.5 μm in size (PM2.5), carbon monoxide (CO), endotoxin in inhalable dust and carbon dioxide (CO2), together with 2-3 week averaged concentrations of nitrogen dioxide (NO2) were collected in 100 houses during the winter and spring of 2009-2010. The geometric mean of the 24-h time-weighted-average (TWA) PM2.5 concentration was highest in homes with resident smokers (99 μg/m3--much higher than the WHO 24-h guidance value of 25 μg/m3). Lower geometric mean 24-h TWA levels were found in homes that burned coal (7 μg/m3) or wood (6 μg/m3) and in homes with gas cookers (7 μg/m3). In peat-burning homes, the average 24-h PM2.5 level recorded was 11 μg/m3. Airborne endotoxin, CO, CO2, and NO2 concentrations were generally within indoor air quality guidance levels.

PRACTICAL IMPLICATIONS

Little is known about indoor air quality (IAQ) in homes that burn solid or fossil-derived fuels in economically developed countries. Recent legislative changes have moved to improve IAQ at work and in enclosed public places, but there remains a real need to begin the process of quantifying the health burden that arises from indoor air pollution within domestic environments. This study demonstrates that homes in Scotland and Ireland that burn solid fuels or gas for heating and cooking have concentrations of air pollutants generally within guideline levels. Homes where combustion of cigarettes takes place have much poorer air quality.

Wood smoke exposure, poverty and impaired lung function in Malawian adults

BACKGROUND

Household air pollution from burning biomass fuel is increasingly recognised as a major global health concern. Biomass smoke is associated with chronic obstructive pulmonary disease (COPD) in Asian and Central American countries, but there are few data from Africa.

METHODS

We hypothesised that reported wood smoke as compared to charcoal smoke exposure would be associated with a reduction in forced expiratory volume in 1 second in Malawian adults. Volunteers from urban and rural locations performed spirometry and completed a questionnaire assessing lifestyle, including smoke exposure and symptoms.

RESULTS

In total, 374 adults were recruited; 61% were female; 160 cooked using charcoal and 174 used wood. Individuals who used wood as their main domestic fuel had significantly worse lung function than those who used charcoal. Significant factors associated with impaired lung function in the multivariate model were age, sex, height, wood smoke exposure, poverty, smoking and previous tuberculosis.

CONCLUSION

Our data suggest that wood smoke and poverty contribute to reduced lung function in rural Africans and that COPD is common in this population. The use of charcoal in rural populations may be relatively protective, and this idea merits further study. The risk factors for impaired lung function in Malawi are multiple and require more detailed characterisation to plan appropriate health interventions.

Parental occupation is a risk factor for childhood wheeze and asthma

The present birth cohort study investigated whether or not childhood wheeze and asthma are associated with parental exposure to occupational sensitisers that cause asthma. Parental occupation, from the Avon Longitudinal Study of Parents and Children (ALSPAC), was related to wheeze, asthma, ventilatory function, airway responsiveness and atopic sensitisation in children aged 0-102 months. Occupation was recorded for 11,193 mothers and 9,473 fathers antenatally, and for 4,631 mothers and 5,315 fathers post-natally. Childhood respiratory outcomes were not associated with parental occupational exposure to diisocyanates, glues/resins, dyes, animal dust, solder, enzymes and wood dust. Maternal post-natal occupational exposure to latex and/or biocides/fungicides increased the likelihood of childhood wheeze and asthma. High levels of latex or biocide/fungicide exposure were associated with an OR (95% CI) of 1.26 (1.07-1.50) and 1.22 (1.02-2.05), respectively, for wheezing up to 81 months. Combined maternal latex and biocide/fungicide exposure increased the likelihood of childhood wheeze (1.22 (1.03-1.43)) and asthma. High paternal occupational flour dust exposure was associated with an increased likelihood of wheeze after 30 months (2.31 (1.05-5.10)) and asthma by 91 months (3.23 (1.34-7.79)). Maternal occupational exposure to latex and/or biocides and paternal exposure to flour dust increases the risk of childhood asthma. Further studies in this area are justified.

Biomass fuel use and indoor air pollution in homes in Malawi

Background:

Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. The work describes the nature and quantity of smoke exposure from biomass fuel in Malawian homes.

Methods:

Markers of indoor air quality were measured in 62 homes (31 rural and 31 urban) over a typical 24 h period. Four different devices were used (one gravimetric device, two photometric devices and a carbon monoxide (HOBO) monitor. Gravimetric samples were analysed for transition metal content. Data on cooking and lighting fuel type together with information on indicators of socioeconomic status were collected by questionnaire.

Results:

Respirable dust levels in both the urban and rural environment were high with the mean (SD) 24 h average levels being 226 μg/m³ (206 μg/m³). Data from real-time instruments indicated respirable dust concentrations were >250 μg/m³ for >1 h per day in 52% of rural homes and 17% of urban homes. Average carbon monoxide levels were significantly higher in urban compared with rural homes (6.14 ppm vs 1.87 ppm; p<0.001). The transition metal content of the smoke was low, with no significant difference found between urban and rural homes.

Conclusions:

Indoor air pollution levels in Malawian homes are high. Further investigation is justified because the levels that we have demonstrated are hazardous and are likely to be damaging to health. Interventions should be sought to reduce exposure to concentrations less harmful to health.

Bar workers' health and environmental tobacco smoke exposure (BHETSE): symptomatic improvement in bar staff following smoke-free legislation in Scotland

OBJECTIVE

To examine changes in the health of bar workers after smoke-free legislation was introduced.

DESIGN

Longitudinal study following bar workers from before legislation introduction, at 2 months after introduction and at 1 year to control for seasonal differences.

SETTING

Bars across a range of socio-economic settings in Scotland.

PARTICIPANTS

371 bar workers recruited from 72 bars.

INTERVENTION

Introduction of smoke-free legislation prohibiting smoking in enclosed public places, including bars.

MAIN OUTCOMES MEASURES

Change in prevalence of self-reported respiratory and sensory symptoms.

RESULTS

Of the 191 (51%) workers seen at 1-year follow-up, the percentage reporting any respiratory symptom fell from 69% to 57% (p = 0.02) and for sensory symptoms from 75% to 64% (p = 0.02) following reductions in exposure, effects being greater at 2 months, probably partly due to seasonal effects. Excluding respondents who reported having a cold at either baseline or 1 year, the reduction in respiratory symptoms was similar although greater for "any" sensory symptom (69% falling to 54%, p = 0.011). For non-smokers (n = 57) the reductions in reported symptoms were significant for phlegm production (32% to 14%, p = 0.011) and red/irritated eyes (44% to 18%, p = 0.001). Wheeze (48% to 31%, p = 0.006) and breathlessness (42% to 29%, p = 0.038) improved significantly in smokers. There was no relationship between change in salivary cotinine levels and change in symptoms.

CONCLUSIONS

Bar workers in Scotland reported significantly fewer respiratory and sensory symptoms 1 year after their working environment became smoke free. As these improvements, controlled for seasonal variations, were seen in both non-smokers and smokers, smoke-free working environments may have potentially important benefits even for smokers.

Sodium metabisulphite induced airways disease in the fishing and fish-processing industry

BACKGROUND

Sodium metabisulphite (SMBS) is recognized as a potential cause of airway irritation and possibly occupational asthma, but awareness of its use in the fishing and fish-processing industry is low.

AIMS AND METHODS

To describe three cases of occupational airways disease due to SMBS exposure and to review the literature.

RESULTS

Three patients, one trawlerman and two prawn processors, developed work-related airways disease due to exposure to SMBS, one with irritant-induced asthma with a positive-specific bronchial challenge associated with very high sulphur dioxide exposures, one with occupational asthma and one with vocal cord dysfunction and underlying asthma. Of the nine cases recorded in the literature, most were non-atopic and responses to specific bronchial challenge when undertaken showed an immediate response. Exposures to sulphur dioxide in these settings are very high, in excess of 30 ppm.

CONCLUSION

SMBS should be regarded as a cause of occupational airways disease and its use in the fish and prawn-processing industry investigated further to better identify risks from exposure and handling of the agent in the workplace.

Changes in air quality and second-hand smoke exposure in hospitality sector businesses after introduction of the English Smoke-free legislation

BACKGROUND

To monitor and disseminate the short-term effects of the English Smoke-free legislation on air quality and employee exposure in businesses of the hospitality industry.

METHODS

Indoor particle concentrations and salivary cotinine levels were measured in businesses in the hospitality sector and non-smoking employees one month before and after the implementation of the legislation. Results were immediately released to the media to announce the improvements in air quality and employee exposure to the wider public.

RESULTS

Measurements were collected in 49 businesses and from 75 non-smoking individuals. Indoor PM(2.5) concentrations decreased by 95% from 217 microg/m(3) at baseline to 11 microg/m(3) at follow-up (P < 0.001). Salivary cotinine in employees was reduced by 75%, from 3.6 ng/ml at baseline to 0.9 ng/ml at follow-up (P < 0.001). The findings were presented to the public through press releases and interviews and were cited in over 20 media articles.

CONCLUSION

The project demonstrates the positive effects of the English Smoke-free legislation on air quality and second-hand smoke exposure in the hospitality industry sector. We believe that quick and positive feedback to the public on the effects of smoking restrictions is essential when introducing public health legislation such as the Smoke-free legislation.